diff --git a/apps/theming/appinfo/app.php b/apps/theming/appinfo/app.php
index 76580879ca112..5ef506e5acd26 100644
--- a/apps/theming/appinfo/app.php
+++ b/apps/theming/appinfo/app.php
@@ -31,7 +31,7 @@
 		'v' => \OC::$server->getConfig()->getAppValue('theming', 'cachebuster', '0'),
 	]
 );
-\OC_Util::addHeader(
+\OCP\Util::addHeader(
 	'link',
 	[
 		'rel' => 'stylesheet',
diff --git a/apps/theming/appinfo/routes.php b/apps/theming/appinfo/routes.php
index 073dacb789c71..e062a68d69df8 100644
--- a/apps/theming/appinfo/routes.php
+++ b/apps/theming/appinfo/routes.php
@@ -24,9 +24,7 @@
  *
  */
 
-namespace OCA\Theming\AppInfo;
-
-(new \OCP\AppFramework\App('theming'))->registerRoutes($this, array('routes' => array(
+return ['routes' => [
 	[
 		'name' => 'Theming#updateStylesheet',
 		'url' => '/ajax/updateStylesheet',
@@ -57,5 +55,5 @@
 		'url' => '/loginbackground',
 		'verb' => 'GET',
 	],
-)));
+]];
 
diff --git a/apps/theming/lib/controller/themingcontroller.php b/apps/theming/lib/Controller/ThemingController.php
similarity index 79%
rename from apps/theming/lib/controller/themingcontroller.php
rename to apps/theming/lib/Controller/ThemingController.php
index 6f8af0bb78c55..8d9869b84a7c6 100644
--- a/apps/theming/lib/controller/themingcontroller.php
+++ b/apps/theming/lib/Controller/ThemingController.php
@@ -30,7 +30,10 @@
 use OCA\Theming\Template;
 use OCP\AppFramework\Controller;
 use OCP\AppFramework\Http;
+use OCP\AppFramework\Http\DataDownloadResponse;
 use OCP\AppFramework\Http\DataResponse;
+use OCP\AppFramework\Http\StreamResponse;
+use OCP\AppFramework\Utility\ITimeFactory;
 use OCP\Files\IRootFolder;
 use OCP\IConfig;
 use OCP\IL10N;
@@ -47,6 +50,10 @@
 class ThemingController extends Controller {
 	/** @var Template */
 	private $template;
+	/** @var Util */
+	private $util;
+	/** @var ITimeFactory */
+	private $timeFactory;
 	/** @var IL10N */
 	private $l;
 	/** @var IConfig */
@@ -61,6 +68,8 @@ class ThemingController extends Controller {
 	 * @param IRequest $request
 	 * @param IConfig $config
 	 * @param Template $template
+	 * @param Util $util
+	 * @param ITimeFactory $timeFactory
 	 * @param IL10N $l
 	 * @param IRootFolder $rootFolder
 	 */
@@ -69,12 +78,16 @@ public function __construct(
 		IRequest $request,
 		IConfig $config,
 		Template $template,
+		Util $util,
+		ITimeFactory $timeFactory,
 		IL10N $l,
 		IRootFolder $rootFolder
 	) {
 		parent::__construct($appName, $request);
 
 		$this->template = $template;
+		$this->util = $util;
+		$this->timeFactory = $timeFactory;
 		$this->l = $l;
 		$this->config = $config;
 		$this->rootFolder = $rootFolder;
@@ -87,6 +100,50 @@ public function __construct(
 	 * @internal param string $color
 	 */
 	public function updateStylesheet($setting, $value) {
+		$value = trim($value);
+		switch ($setting) {
+			case 'name':
+				if (strlen($value) > 250) {
+					return new DataResponse([
+						'data' => [
+							'message' => $this->l->t('The given name is too long'),
+						],
+						'status' => 'error'
+					]);
+				}
+				break;
+			case 'url':
+				if (strlen($value) > 500) {
+					return new DataResponse([
+						'data' => [
+							'message' => $this->l->t('The given web address is too long'),
+						],
+						'status' => 'error'
+					]);
+				}
+				break;
+			case 'slogan':
+				if (strlen($value) > 500) {
+					return new DataResponse([
+						'data' => [
+							'message' => $this->l->t('The given slogan is too long'),
+						],
+						'status' => 'error'
+					]);
+				}
+				break;
+			case 'color':
+				if (!preg_match('/^\#([0-9a-f]{3}|[0-9a-f]{6})$/i', $value)) {
+					return new DataResponse([
+						'data' => [
+							'message' => $this->l->t('The given color is invalid'),
+						],
+						'status' => 'error'
+					]);
+				}
+				break;
+		}
+
 		$this->template->set($setting, $value);
 		return new DataResponse(
 			[
@@ -166,7 +223,7 @@ public function undo($setting) {
 	 * @PublicPage
 	 * @NoCSRFRequired
 	 *
-	 * @return Http\StreamResponse
+	 * @return StreamResponse|DataResponse
 	 */
 	public function getLogo() {
 		$pathToLogo = $this->config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data/') . '/themedinstancelogo';
@@ -174,10 +231,9 @@ public function getLogo() {
 			return new DataResponse();
 		}
 
-		\OC_Response::setExpiresHeader(gmdate('D, d M Y H:i:s', time() + (60*60*24*45)) . ' GMT');
-		\OC_Response::enableCaching();
 		$response = new Http\StreamResponse($pathToLogo);
 		$response->cacheFor(3600);
+		$response->addHeader('Expires', date(\DateTime::RFC2822, $this->timeFactory->getTime()));
 		$response->addHeader('Content-Disposition', 'attachment');
 		$response->addHeader('Content-Type', $this->config->getAppValue($this->appName, 'logoMime', ''));
 		return $response;
@@ -187,7 +243,7 @@ public function getLogo() {
 	 * @PublicPage
 	 * @NoCSRFRequired
 	 *
-	 * @return Http\StreamResponse
+	 * @return StreamResponse|DataResponse
 	 */
 	public function getLoginBackground() {
 		$pathToLogo = $this->config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data/') . '/themedbackgroundlogo';
@@ -195,10 +251,9 @@ public function getLoginBackground() {
 			return new DataResponse();
 		}
 
-		\OC_Response::setExpiresHeader(gmdate('D, d M Y H:i:s', time() + (60*60*24*45)) . ' GMT');
-		\OC_Response::enableCaching();
-		$response = new Http\StreamResponse($pathToLogo);
+		$response = new StreamResponse($pathToLogo);
 		$response->cacheFor(3600);
+		$response->addHeader('Expires', date(\DateTime::RFC2822, $this->timeFactory->getTime()));
 		$response->addHeader('Content-Disposition', 'attachment');
 		$response->addHeader('Content-Type', $this->config->getAppValue($this->appName, 'backgroundMime', ''));
 		return $response;
@@ -208,13 +263,13 @@ public function getLoginBackground() {
 	 * @NoCSRFRequired
 	 * @PublicPage
 	 *
-	 * @return Http\DataDownloadResponse
+	 * @return DataDownloadResponse
 	 */
 	public function getStylesheet() {
 		$cacheBusterValue = $this->config->getAppValue('theming', 'cachebuster', '0');
 		$responseCss = '';
 		$color = $this->config->getAppValue($this->appName, 'color');
-		$elementColor = Util::elementColor($color);
+		$elementColor = $this->util->elementColor($color);
 		if($color !== '') {
 			$responseCss .= sprintf(
 				'#body-user #header,#body-settings #header,#body-public #header,#body-login,.searchbox input[type="search"]:focus,.searchbox input[type="search"]:active,.searchbox input[type="search"]:valid {background-color: %s}' . "\n",
@@ -229,7 +284,7 @@ public function getStylesheet() {
 				$elementColor
 			);
 			$responseCss .= 'input[type="radio"].radio:checked:not(.radio--white):not(:disabled) + label:before {' .
-				'background-image: url(\'data:image/svg+xml;base64,'.Util::generateRadioButton($elementColor).'\');' .
+				'background-image: url(\'data:image/svg+xml;base64,'.$this->util->generateRadioButton($elementColor).'\');' .
 				"}\n";
 			$responseCss .= '
 				#firstrunwizard .firstrunwizard-header {
@@ -265,16 +320,15 @@ public function getStylesheet() {
 				'background-image: url(\'./loginbackground?v='.$cacheBusterValue.'\');' .
 			'}' . "\n";
 		}
-		if(Util::invertTextColor($color)) {
+		if($this->util->invertTextColor($color)) {
 			$responseCss .= '#header .header-appname, #expandDisplayName { color: #000000; }' . "\n";
 			$responseCss .= '#header .icon-caret { background-image: url(\'' . \OC::$WEBROOT . '/core/img/actions/caret-dark.svg\'); }' . "\n";
 			$responseCss .= '.searchbox input[type="search"] { background: transparent url(\'' . \OC::$WEBROOT . '/core/img/actions/search.svg\') no-repeat 6px center; color: #000; }' . "\n";
 			$responseCss .= '.searchbox input[type="search"]:focus,.searchbox input[type="search"]:active,.searchbox input[type="search"]:valid { color: #000; border: 1px solid rgba(0, 0, 0, .5); }' . "\n";
 		}
 
-		\OC_Response::setExpiresHeader(gmdate('D, d M Y H:i:s', time() + (60*60*24*45)) . ' GMT');
-		\OC_Response::enableCaching();
-		$response = new Http\DataDownloadResponse($responseCss, 'style', 'text/css');
+		$response = new DataDownloadResponse($responseCss, 'style', 'text/css');
+		$response->addHeader('Expires', date(\DateTime::RFC2822, $this->timeFactory->getTime()));
 		$response->cacheFor(3600);
 		return $response;
 	}
diff --git a/apps/theming/lib/template.php b/apps/theming/lib/Template.php
similarity index 99%
rename from apps/theming/lib/template.php
rename to apps/theming/lib/Template.php
index 8cd2befc1d112..25730aad95b14 100644
--- a/apps/theming/lib/template.php
+++ b/apps/theming/lib/Template.php
@@ -40,7 +40,7 @@
 class Template extends \OC_Defaults {
 	/** @var IConfig */
 	private $config;
-	/** @var  IL10N */
+	/** @var IL10N */
 	private $l;
 	/** @var IURLGenerator */
 	private $urlGenerator;
diff --git a/apps/theming/lib/util.php b/apps/theming/lib/Util.php
similarity index 87%
rename from apps/theming/lib/util.php
rename to apps/theming/lib/Util.php
index f0ce30ac5ba7d..71ed0958e42a9 100644
--- a/apps/theming/lib/util.php
+++ b/apps/theming/lib/Util.php
@@ -29,8 +29,8 @@ class Util {
 	 * @param string $color rgb color value
 	 * @return bool
 	 */
-	public static function invertTextColor($color) {
-		$l = self::calculateLuminance($color);
+	public function invertTextColor($color) {
+		$l = $this->calculateLuminance($color);
 		if($l>0.5) {
 			return true;
 		} else {
@@ -44,8 +44,8 @@ public static function invertTextColor($color) {
 	 * @param $color
 	 * @return string
 	 */
-	public static function elementColor($color) {
-		$l = self::calculateLuminance($color);
+	public function elementColor($color) {
+		$l = $this->calculateLuminance($color);
 		if($l>0.8) {
 			return '#555555';
 		} else {
@@ -57,7 +57,7 @@ public static function elementColor($color) {
 	 * @param string $color rgb color value
 	 * @return float
 	 */
-	public static function calculateLuminance($color) {
+	public function calculateLuminance($color) {
 		$hex = preg_replace("/[^0-9A-Fa-f]/", '', $color);
 		if (strlen($hex) === 3) {
 			$hex = $hex{0} . $hex{0} . $hex{1} . $hex{1} . $hex{2} . $hex{2};
@@ -75,7 +75,7 @@ public static function calculateLuminance($color) {
 	 * @param $color
 	 * @return string base64 encoded radio button svg
 	 */
-	public static function generateRadioButton($color) {
+	public function generateRadioButton($color) {
 		$radioButtonIcon = '<svg xmlns="http://www.w3.org/2000/svg" height="16" width="16">' .
 			'<path d="M8 1a7 7 0 0 0-7 7 7 7 0 0 0 7 7 7 7 0 0 0 7-7 7 7 0 0 0-7-7zm0 1a6 6 0 0 1 6 6 6 6 0 0 1-6 6 6 6 0 0 1-6-6 6 6 0 0 1 6-6zm0 2a4 4 0 1 0 0 8 4 4 0 0 0 0-8z" fill="'.$color.'"/></svg>';
 		return base64_encode($radioButtonIcon);
diff --git a/apps/theming/settings/settings-admin.php b/apps/theming/settings/settings-admin.php
index d9aa05cfca064..8ef499789e899 100644
--- a/apps/theming/settings/settings-admin.php
+++ b/apps/theming/settings/settings-admin.php
@@ -23,8 +23,6 @@
  *
  */
 
-\OC_Util::checkAdminUser();
-
 $config = \OC::$server->getConfig();
 $l = \OC::$server->getL10N('theming');
 $urlGenerator = \OC::$server->getURLGenerator();
@@ -40,7 +38,7 @@
 	$errorMessage = $l->t('You already use a custom theme');
 }
 
-$template = new OCP\Template('theming', 'settings-admin');
+$template = new \OCP\Template('theming', 'settings-admin');
 
 $template->assign('themable', $themable);
 $template->assign('errorMessage', $errorMessage);
diff --git a/apps/theming/templates/settings-admin.php b/apps/theming/templates/settings-admin.php
index 27cdd8b60a3d4..3589812070e07 100644
--- a/apps/theming/templates/settings-admin.php
+++ b/apps/theming/templates/settings-admin.php
@@ -15,25 +15,25 @@
 	<?php } else { ?>
 	<p>
 		<label><span><?php p($l->t('Name')) ?></span>
-			<input id="theming-name" type="text" placeholder="<?php p($l->t('Name')); ?>" value="<?php p($_['name']) ?>" />
+			<input id="theming-name" type="text" placeholder="<?php p($l->t('Name')); ?>" value="<?php p($_['name']) ?>" maxlength="250" />
 		</label>
 		<span data-setting="name" data-toggle="tooltip" data-original-title="<?php p($l->t('reset to default')); ?>" class="theme-undo icon icon-history"></span>
 	</p>
 	<p>
 		<label><span><?php p($l->t('Web address')) ?></span>
-			<input id="theming-url" type="text" placeholder="<?php p($l->t('Web address https://…')); ?>" value="<?php p($_['url']) ?>" />
+			<input id="theming-url" type="text" placeholder="<?php p($l->t('Web address https://…')); ?>" value="<?php p($_['url']) ?>" maxlength="500" />
 		</label>
 		<span data-setting="url" data-toggle="tooltip" data-original-title="<?php p($l->t('reset to default')); ?>" class="theme-undo icon icon-history"></span>
 	</p>
 	<p>
 		<label><span><?php p($l->t('Slogan')) ?></span>
-			<input id="theming-slogan" type="text" placeholder="<?php p($l->t('Slogan')); ?>" value="<?php p($_['slogan']) ?>" />
+			<input id="theming-slogan" type="text" placeholder="<?php p($l->t('Slogan')); ?>" value="<?php p($_['slogan']) ?>" maxlength="500" />
 		</label>
 		<span data-setting="slogan" data-toggle="tooltip" data-original-title="<?php p($l->t('reset to default')); ?>" class="theme-undo icon icon-history"></span>
 	</p>
 	<p>
 		<label><span><?php p($l->t('Color')) ?></span>
-			<input id="theming-color" type="text" class="jscolor" value="<?php p($_['color']) ?>" />
+			<input id="theming-color" type="text" class="jscolor" maxlength="6" value="<?php p($_['color']) ?>" />
 		</label>
 		<span data-setting="color" data-toggle="tooltip" data-original-title="<?php p($l->t('reset to default')); ?>" class="theme-undo icon icon-history"></span>
 	</p>
diff --git a/apps/theming/tests/lib/controller/ThemingControllerTest.php b/apps/theming/tests/Controller/ThemingControllerTest.php
similarity index 85%
rename from apps/theming/tests/lib/controller/ThemingControllerTest.php
rename to apps/theming/tests/Controller/ThemingControllerTest.php
index c9b55001f8c22..82eb8259af58a 100644
--- a/apps/theming/tests/lib/controller/ThemingControllerTest.php
+++ b/apps/theming/tests/Controller/ThemingControllerTest.php
@@ -36,32 +36,46 @@
 use Test\TestCase;
 
 class ThemingControllerTest extends TestCase {
-	/** @var IRequest */
+	/** @var IRequest|\PHPUnit_Framework_MockObject_MockObject */
 	private $request;
-	/** @var IConfig */
+	/** @var IConfig|\PHPUnit_Framework_MockObject_MockObject */
 	private $config;
-	/** @var Template */
+	/** @var Template|\PHPUnit_Framework_MockObject_MockObject */
 	private $template;
-	/** @var IL10N */
+	/** @var Util */
+	private $util;
+	/** @var \OCP\AppFramework\Utility\ITimeFactory */
+	private $timeFactory;
+	/** @var IL10N|\PHPUnit_Framework_MockObject_MockObject */
 	private $l10n;
 	/** @var ThemingController */
 	private $themingController;
-	/** @var IRootFolder */
+	/** @var IRootFolder|\PHPUnit_Framework_MockObject_MockObject */
 	private $rootFolder;
 
 	public function setUp() {
-		$this->request = $this->getMock('\\OCP\\IRequest');
-		$this->config = $this->getMock('\\OCP\\IConfig');
-		$this->template = $this->getMockBuilder('\\OCA\\Theming\\Template')
+		$this->request = $this->getMockBuilder('OCP\IRequest')->getMock();
+		$this->config = $this->getMockBuilder('OCP\IConfig')->getMock();
+		$this->template = $this->getMockBuilder('OCA\Theming\Template')
 			->disableOriginalConstructor()->getMock();
-		$this->l10n = $this->getMock('\\OCP\\IL10N');
-		$this->rootFolder = $this->getMock('\\OCP\\Files\\IRootFolder');
+		$this->util = new Util();
+		$this->timeFactory = $this->getMockBuilder('OCP\AppFramework\Utility\ITimeFactory')
+			->disableOriginalConstructor()
+			->getMock();
+		$this->l10n = $this->getMockBuilder('OCP\IL10N')->getMock();
+		$this->rootFolder = $this->getMockBuilder('OCP\Files\IRootFolder')->getMock();
+
+		$this->timeFactory->expects($this->any())
+			->method('getTime')
+			->willReturn(123);
 
 		$this->themingController = new ThemingController(
 			'theming',
 			$this->request,
 			$this->config,
 			$this->template,
+			$this->util,
+			$this->timeFactory,
 			$this->l10n,
 			$this->rootFolder
 		);
@@ -69,27 +83,48 @@ public function setUp() {
 		return parent::setUp();
 	}
 
-	public function testUpdateStylesheet() {
+	public function dataUpdateStylesheet() {
+		return [
+			['name', str_repeat('a', 250), 'success', 'Saved'],
+			['name', str_repeat('a', 251), 'error', 'The given name is too long'],
+			['url', str_repeat('a', 500), 'success', 'Saved'],
+			['url', str_repeat('a', 501), 'error', 'The given web address is too long'],
+			['slogan', str_repeat('a', 500), 'success', 'Saved'],
+			['slogan', str_repeat('a', 501), 'error', 'The given slogan is too long'],
+			['color', '#0082c9', 'success', 'Saved'],
+			['color', '#0082C9', 'success', 'Saved'],
+			['color', '0082C9', 'error', 'The given color is invalid'],
+			['color', '#0082Z9', 'error', 'The given color is invalid'],
+			['color', 'Nextcloud', 'error', 'The given color is invalid'],
+		];
+	}
+
+	/**
+	 * @dataProvider dataUpdateStylesheet
+	 *
+	 * @param string $setting
+	 * @param string $value
+	 * @param string $status
+	 * @param string $message
+	 */
+	public function testUpdateStylesheet($setting, $value, $status, $message) {
 		$this->template
-			->expects($this->once())
+			->expects($status === 'success' ? $this->once() : $this->never())
 			->method('set')
-			->with('MySetting', 'MyValue');
+			->with($setting, $value);
 		$this->l10n
 			->expects($this->once())
 			->method('t')
-			->with('Saved')
-			->willReturn('Saved');
+			->with($message)
+			->willReturn($message);
 
-		$expected = new DataResponse(
-			[
-				'data' =>
-					[
-						'message' => 'Saved',
-					],
-				'status' => 'success'
-			]
-		);
-		$this->assertEquals($expected, $this->themingController->updateStylesheet('MySetting', 'MyValue'));
+		$expected = new DataResponse([
+			'data' => [
+				'message' => $message,
+			],
+			'status' => $status,
+		]);
+		$this->assertEquals($expected, $this->themingController->updateStylesheet($setting, $value));
 	}
 
 	public function testUpdateLogoNoData() {
@@ -273,6 +308,7 @@ public function testGetLogo() {
 
 		@$expected = new Http\StreamResponse($tmpLogo);
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		$expected->addHeader('Content-Disposition', 'attachment');
 		$expected->addHeader('Content-Type', 'text/svg');
 		@$this->assertEquals($expected, $this->themingController->getLogo());
@@ -301,6 +337,7 @@ public function testGetLoginBackground() {
 
 		@$expected = new Http\StreamResponse($tmpLogo);
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		$expected->addHeader('Content-Disposition', 'attachment');
 		$expected->addHeader('Content-Type', 'image/png');
 		@$this->assertEquals($expected, $this->themingController->getLoginBackground());
@@ -344,7 +381,7 @@ public function testGetStylesheetWithOnlyColor() {
 			$color
 		);
 		$expectedData .= 'input[type="radio"].radio:checked:not(.radio--white):not(:disabled) + label:before {' .
-			'background-image: url(\'data:image/svg+xml;base64,'.Util::generateRadioButton($color).'\');' .
+			'background-image: url(\'data:image/svg+xml;base64,'.$this->util->generateRadioButton($color).'\');' .
 			"}\n";
 
 		$expectedData .= '
@@ -359,6 +396,7 @@ public function testGetStylesheetWithOnlyColor() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
 
@@ -399,7 +437,7 @@ public function testGetStylesheetWithOnlyColorInvert() {
 			\OC::$WEBROOT
 		);
 		$expectedData .= 'input[type="radio"].radio:checked:not(.radio--white):not(:disabled) + label:before {' .
-			'background-image: url(\'data:image/svg+xml;base64,'.Util::generateRadioButton('#555555').'\');' .
+			'background-image: url(\'data:image/svg+xml;base64,'.$this->util->generateRadioButton('#555555').'\');' .
 			"}\n";
 
 		$expectedData .= '
@@ -419,6 +457,7 @@ public function testGetStylesheetWithOnlyColorInvert() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
 
@@ -460,6 +499,7 @@ public function testGetStylesheetWithOnlyHeaderLogo() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
 
@@ -493,6 +533,7 @@ public function testGetStylesheetWithOnlyBackgroundLogin() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
 
@@ -534,7 +575,7 @@ public function testGetStylesheetWithAllCombined() {
 			$color
 		);
 		$expectedData .= 'input[type="radio"].radio:checked:not(.radio--white):not(:disabled) + label:before {' .
-			'background-image: url(\'data:image/svg+xml;base64,'.Util::generateRadioButton($color).'\');' .
+			'background-image: url(\'data:image/svg+xml;base64,'.$this->util->generateRadioButton($color).'\');' .
 			"}\n";
 		$expectedData .= '
 				#firstrunwizard .firstrunwizard-header {
@@ -565,6 +606,7 @@ public function testGetStylesheetWithAllCombined() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
 
@@ -606,7 +648,7 @@ public function testGetStylesheetWithAllCombinedInverted() {
 			\OC::$WEBROOT
 		);
 		$expectedData .= 'input[type="radio"].radio:checked:not(.radio--white):not(:disabled) + label:before {' .
-			'background-image: url(\'data:image/svg+xml;base64,'.Util::generateRadioButton('#555555').'\');' .
+			'background-image: url(\'data:image/svg+xml;base64,'.$this->util->generateRadioButton('#555555').'\');' .
 			"}\n";
 		$expectedData .= '
 				#firstrunwizard .firstrunwizard-header {
@@ -641,7 +683,7 @@ public function testGetStylesheetWithAllCombinedInverted() {
 		$expected = new Http\DataDownloadResponse($expectedData, 'style', 'text/css');
 
 		$expected->cacheFor(3600);
+		$expected->addHeader('Expires', date(\DateTime::RFC2822, 123));
 		@$this->assertEquals($expected, $this->themingController->getStylesheet());
 	}
-
 }
diff --git a/apps/theming/tests/lib/TemplateTest.php b/apps/theming/tests/TemplateTest.php
similarity index 100%
rename from apps/theming/tests/lib/TemplateTest.php
rename to apps/theming/tests/TemplateTest.php
diff --git a/apps/theming/tests/lib/UtilTest.php b/apps/theming/tests/UtilTest.php
similarity index 78%
rename from apps/theming/tests/lib/UtilTest.php
rename to apps/theming/tests/UtilTest.php
index cf64b389d113b..c7fc385d25d9b 100644
--- a/apps/theming/tests/lib/UtilTest.php
+++ b/apps/theming/tests/UtilTest.php
@@ -27,62 +27,70 @@
 
 class UtilTest extends TestCase {
 
+	/** @var Util */
+	protected $util;
+
+	protected function setUp() {
+		parent::setUp();
+		$this->util = new Util();
+	}
+
 	public function testInvertTextColorLight() {
-		$invert = Util::invertTextColor('#ffffff');
+		$invert = $this->util->invertTextColor('#ffffff');
 		$this->assertEquals(true, $invert);
 	}
 
 	public function testInvertTextColorDark() {
-		$invert = Util::invertTextColor('#000000');
+		$invert = $this->util->invertTextColor('#000000');
 		$this->assertEquals(false, $invert);
 	}
 
 	public function testCalculateLuminanceLight() {
-		$luminance = Util::calculateLuminance('#ffffff');
+		$luminance = $this->util->calculateLuminance('#ffffff');
 		$this->assertEquals(1, $luminance);
 	}
 
 	public function testCalculateLuminanceDark() {
-		$luminance = Util::calculateLuminance('#000000');
+		$luminance = $this->util->calculateLuminance('#000000');
 		$this->assertEquals(0, $luminance);
 	}
 
 	public function testCalculateLuminanceLightShorthand() {
-		$luminance = Util::calculateLuminance('#fff');
+		$luminance = $this->util->calculateLuminance('#fff');
 		$this->assertEquals(1, $luminance);
 	}
 
 	public function testCalculateLuminanceDarkShorthand() {
-		$luminance = Util::calculateLuminance('#000');
+		$luminance = $this->util->calculateLuminance('#000');
 		$this->assertEquals(0, $luminance);
 	}
 	public function testInvertTextColorInvalid() {
-		$invert = Util::invertTextColor('aaabbbcccddd123');
+		$invert = $this->util->invertTextColor('aaabbbcccddd123');
 		$this->assertEquals(false, $invert);
 	}
 	
 	public function testInvertTextColorEmpty() {
-		$invert = Util::invertTextColor('');
+		$invert = $this->util->invertTextColor('');
 		$this->assertEquals(false, $invert);
 	}
 
 	public function testElementColorDefault() {
-		$elementColor = Util::elementColor("#000000");
+		$elementColor = $this->util->elementColor("#000000");
 		$this->assertEquals('#000000', $elementColor);
 	}
 
 	public function testElementColorOnBrightBackground() {
-		$elementColor = Util::elementColor('#ffffff');
+		$elementColor = $this->util->elementColor('#ffffff');
 		$this->assertEquals('#555555', $elementColor);
 	}
 
 	public function testGenerateRadioButtonWhite() {
-		$button = Util::generateRadioButton('#ffffff');
+		$button = $this->util->generateRadioButton('#ffffff');
 		$expected = 'PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIGhlaWdodD0iMTYiIHdpZHRoPSIxNiI+PHBhdGggZD0iTTggMWE3IDcgMCAwIDAtNyA3IDcgNyAwIDAgMCA3IDcgNyA3IDAgMCAwIDctNyA3IDcgMCAwIDAtNy03em0wIDFhNiA2IDAgMCAxIDYgNiA2IDYgMCAwIDEtNiA2IDYgNiAwIDAgMS02LTYgNiA2IDAgMCAxIDYtNnptMCAyYTQgNCAwIDEgMCAwIDggNCA0IDAgMCAwIDAtOHoiIGZpbGw9IiNmZmZmZmYiLz48L3N2Zz4=';
 		$this->assertEquals($expected, $button);
 	}
 	public function testGenerateRadioButtonBlack() {
-		$button = Util::generateRadioButton('#000000');
+		$button = $this->util->generateRadioButton('#000000');
 		$expected = 'PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIGhlaWdodD0iMTYiIHdpZHRoPSIxNiI+PHBhdGggZD0iTTggMWE3IDcgMCAwIDAtNyA3IDcgNyAwIDAgMCA3IDcgNyA3IDAgMCAwIDctNyA3IDcgMCAwIDAtNy03em0wIDFhNiA2IDAgMCAxIDYgNiA2IDYgMCAwIDEtNiA2IDYgNiAwIDAgMS02LTYgNiA2IDAgMCAxIDYtNnptMCAyYTQgNCAwIDEgMCAwIDggNCA0IDAgMCAwIDAtOHoiIGZpbGw9IiMwMDAwMDAiLz48L3N2Zz4=';
 		$this->assertEquals($expected, $button);
 	}